How would it make sense to convert Madoff-type money into Bonds rather than other currencies or gold? It puts an extra step in the process that could foil the plan.
Also, the amount itself is very suspicious. Forgers would be fools to forge such a high amount, which is only realistically purchased by nations, not firms or individuals.
I'm not saying I know what the situation is, but something is very strange here.
I agree the whole thing stinks. But if it were a nation-state with an embassy in Switzerland, why send the money across two borders in suitcases? Diplomatic pounch works a lot better.
So the candidates are: (1) nations without swiss embassies; (2) bad guys. We may get an answer. But we will probably never know the real answer.